1. Field of the Invention
The present invention relates to a print control apparatus that obtains data contained in an image forming apparatus, and that synchronizes the obtained data with a database of an image forming apparatus, method and medium storing a program thereof.
2. Description of the Related Art
Hitherto, a network device management method using SNMP (Simple Network Management Protocol) and MIB (Management Information Base) has been widely known. SNMP is a protocol used for managing devices connected to a network via the network. The network management with SNMP is realized by a configuration including a monitoring terminal (one that monitors) that carries out the network management, that is, an SNMP manager, and a management target device (one that is monitored), that is, an SNMP agent. Hereinafter, the SNMP manager is also simply called a manager, and the SNMP agent is also simply called an agent. In such a configuration, communication is made by a manager making a request to an agent, and an agent returning a response to the manager.
MIB refers to a database that is present in a network device compatible with SNMP and that contains management information with regard to the network device. MIB is configured of a plurality of objects, and information to be stored for each of the objects is defined; those devices containing MIB can set information according to such definitions. For the request made by the manager, the agent returns values, as a response, of the requested MIB object. By analyzing the response returned, the manager can detect what kind of network device is set as the management target and what kind of functions are available.
Generally, image forming apparatuses and print control apparatuses are compatible with SNMP in many cases. In such a case, for example, the print control apparatus and the image forming apparatus can operate as agents, and can return a response to a request from a client PC and the like as the manager. When a print control apparatus operates as an agent, first, the print control apparatus operates as a manager and obtains information from the image forming apparatus. Examples of such information include information relating to the image forming apparatus, such as paper remaining information, toner remaining amount information, counter information, and the like. Then, the print control apparatus obtains such information from the image forming apparatus, sets such information as MIB objects of the print control apparatus itself, and thereafter, returns such information in response to the request from the client PC and the like.
The timing for the print control apparatus to obtain information from the image forming apparatus varies depending on objects, and therefore it is necessary that the obtain processing be carried out at appropriate times. For example, there is a method in which objects are obtained only once from the image forming apparatus when the print control apparatus is started. In another method, objects are obtained from the image forming apparatus by polling the image forming apparatus from the print control apparatus. In yet another method, objects are obtained when an event indicating a status change sent from the image forming apparatus is detected. The print control apparatus is able to update values of MIB objects of the print control apparatus's own at appropriate times combining these methods.
However, when the polling is carried out, for example, while the print control apparatus is sending print data to the image forming apparatus, the possibility of causing collision with a print data packet becomes high. Conventionally, there has been a problem in that when the collision occurred, the print data packet is sent again and as a result, the entire print performance is degraded.
Furthermore, conventionally, the print control apparatus carried out data synchronization with the image forming apparatus by a polling cycle set in the print control apparatus. Therefore, it is possible that the MIB information of the image forming apparatus is already updated immediately before the print control apparatus carries out next polling. When the manager in the network sends a request for obtaining MIB of the print control apparatus in such a case, there may be a case when the values in the response from the print control apparatus are different from the actual values. As a result, the manager cannot obtain the latest MIB values from the print control apparatus.
Japanese Patent Laid-Open No. 2002-149509 has disclosed a network management system that can prevent inconsistency with the MIB setting contents that are referred to by the manager and by each agent. According to this network management system, it is noted that the synchronicity of the network definition information owned by the agent and by the manager can be kept without involvement of manpower. However, there is no particular mention of reducing the network load while there is communication of data other than MIB updates such as print data between the manager and the agent.